The present invention relates to electronic data processing in general, and particularly to application programming.
Applications can be developed using various architectures, including, for example, a model-view-controller (MVC) architecture. The MVC architecture breaks an application into three separate parts—models, views, and controllers. Each model can have multiple views, where each view displays information about the model to a user. A controller of the model receives events, for example, raised by a user interacting with a view to manipulate the model. Each model can have multiple controllers, and a controller can relate to multiple views. The models and the controllers typically include application code. When changes occur in a model, the model updates its views. Data binding is used for data transport between the view and its model or controller. For example, a table view can be defined to display data of a corresponding table that is stored in the model or controller. The table is used as the data source for the table view (data binding). For example, the table view can be replaced by a further view, such as a graph view, that binds against the same table. In this case, the further view displays the table data without changing anything in the controller or the model.
Application development is often divided into two general stages: design time and runtime. Design time can include designing the views of an application (including the layout of the user interface (UI) elements in each view), modeling of the application flow (including the selection of the views to displayed), designing one or more models, and creating and editing other application elements, such as controllers and contexts. Design time can also include the binding of UI elements within the views to data sources that are defined in a data type repository.
Information created during the design time can include application metadata. Application metadata can be stored in a metadata repository, and used as input to the runtime process. During the runtime process, the application metadata can be used to generate the actual runtime code of an application. In some implementations, the application metadata is platform independent, and the generated runtime code is platform specific. The runtime code can be executed in a runtime environment that provides a general framework for running applications. For example, a runtime environment can provide services for deploying and maintaining applications, as well as features such as a caching mechanism that can be used to improve performance, and automatic input assistance and default error handling that is based on the declared application metadata.
Regardless of which architecture is used, it is often desirable to structure an application (including, for example, the models, views, and controllers that make up an MVC application) into reusable entities or components. The reusable components can be embedded by the application, or by another reusable component.